Self-lubricating packing piece

ABSTRACT

PCT No. PCT/SE93/01086 Sec. 371 Date Sep. 16, 1996 Sec. 102(e) Date Sep. 16, 1996 PCT Filed Dec. 17, 1993 PCT Pub. No. WO95/16742 PCT Pub. Date Jun. 22, 1995A seal is provided around an elongated object by providing a plurality of packing pieces having external surfaces, each said packing piece being made of a material composition comprising at least one type of elastomer, and 1-10 percent by weight lubricant, calculated on the total weight of the composition, the lubricant being essentially non-combinable with said elastomer. A bushing is provided around the elongated object, the bushing is packed with the packing pieces, and, in use, the lubricant migrates to the preference, the material composition includes 1-3 percent by weight lubricant, 25-32 percent by weight elastomer, 10-13 percent by weight filler, 1-3 percent by weight activator, 0.01-3 percent by weight accelerator, 0.01-2 percent by weight vulcanizing agent, 35-55 percent by weight flame retardant, 5-8 percent by weight pH-stabilizing agent, 0.01-1 percent by weight of an agent for enhancing cross-linking between rubber and filler, 1-4 percent by weight mould release agent, and 1-3 percent by weight colorant, calculated on the total weight of the material composition. The lubricant is substantially uncombined with any others of these ingredients of the material composition.



